The present invention relates to a measuring method which not only effectively enables the measurement of the velocity of a moving object by the high-speed X-ray CT, for example, the non-destructive test for industrial use (visualization of a moving body), the measurement of a multi-phase flow, the measurement of the distribution of an opaque fluid and the measurement of the cross-section distribution of the flow passage of powder transport, but also enables the high resolution profiling of an object using a same detector module, and its device.
The X-ray CT is usually used to measure the density distribution in a cross section of a resting object at a standstill such as a human organ or a structure. Thus, if the object is an infant who is not resting, or if a structure is incompletely held and moves during the measurement, the signal information for image reconstruction becomes inconsistent, and the movement of the object appears as an artifact on the image. On the other hand, in the high-speed X-ray CT, the scanning speed is as high as 250 exposures a second, which is very high, and even an object moving at the velocity of about 1 m/s can be captured, and the change of the structure inside the object with time can be visualized.
However, the information generally obtained by the X-ray CT is the density distribution in the cross section, and the moving velocity can not be measured in a case where the object shape changes in time like bubbles in a liquid. This is because only a single cross section has been measured by CT, and the velocity of the deforming object must be measured by other measuring devices than the X-ray CT. For example, the high speed X-ray CT disclosed in Japanese Examined Patent Application Publication No. 5-60381 (Official Gazette) (Super-high speed X-ray CT scanner) and Japanese Unexamined Patent Application Publication No. 10-295682 (Official Gazette) (High spatial resolution high-speed X-ray CT scanner) is also served for the CT measurement of the single cross section, but can not obtain the velocity of the moving object accompanying deformation.
A technical problem of the present invention is to provide a method for measuring the velocity of a moving object by the high-speed X-ray CT which is capable of measuring the velocity of the moving object (a deformable body) at the section of measurement which can not be measured by the regular X-ray CT, and its device.
Another technical problem of the present invention is to provide a method for measuring the velocity and the high resolution profile of the moving object which is capable of using the same detector module both for two-sectional CT imaging and the high spatial resolution measurement at one section to measure the velocity of the above-described moving object by a simple means of exchanging slits, and its device.
The method for measuring the velocity of the moving object by the high-speed X-ray CT of the present invention to solve the above-described problems comprises the steps of: simultaneously measuring the internal information at two sections in the moving object using the detector module in which a large number of slender devices formed of a compact semi-conductor for detecting the X-ray are arranged alternately in a projecting manner in the direction opposite to each other so that a part of the devices on end part sides are adjacent to each other, aligning slits with device sparse arrangement portions, respectively, on both end sides of the detector module where the devices are arranged in every other interval, and detecting the X-ray irradiated from an X-ray source and passed through the two slits by the devices; simultaneously measuring the internal information at two sections in the moving object by similarly detecting the X-ray through the above-described two slits after the very short time interval; and comparing the internal information of the moving object measured through the two slits at different times with each other, and obtaining the speed of the moving object based on the time interval when the internal information is closely similar to each other and the interval between the slits.
The high resolution profiling at the single section of the object can also be obtained by aligning the slits over densely arranged portion of the device, and detecting the X-ray irradiated from an X-ray source and passed through the slits by the above-described device.
A velocity measuring technique of the moving object by the high-speed X-ray CT of the present invention comprises a detector module formed by arranging a large number of slender devices formed of a compact semi-conductor for detecting the X-ray in a projecting manner alternately in a direction opposite to each other so that a part of the devices on end part sides are adjacent to each other; slits which are aligned with sparsely arranged portion of the device on both end sides of the above-described detector module where the above-described devices are arranged in every one interval; and an operation control which compares the internal information at two section measured at different times obtained through the simultaneous measurement at two sections of the moving object by the X-ray irradiated from the X-ray source and passed through the two slits with a very short time interval, based on the above-described time interval when the internal information is closely similar to each other and the interval between the above-described slits.
Further, to obtain the high resolution information of the object, the above-described velocity measuring device may be provided with slits to be aligned with the densely arranged portion of the device, and an image picking-up means to obtain the high resolution profile of the object based on the high resolution information at the single section of the object obtained by detecting the X-ray irradiated from the X-ray source and passed through the slits in the above-described device.
In the above-described method and devices of the present invention the internal information at two sections in the moving object can be simultaneously measured by irradiating the X-ray from the same X-ray source through two slits on the device sparse arrangement portion in the detector module in which a part of the devices formed of a compact semi-conductor for detecting the X-ray are arranged adjacent to each other, and the velocity of the moving object can be obtained from the time interval of two measurements and the interval between the above-described two slits by similarly achieving the simultaneous measurement of two sections by the next X-ray irradiation after a very short time interval, comparing the measurement with the data of the existing measurement.
In addition, if the high spatial resolution measurement is necessary, only the slit is exchanged, the single slit is aligned with the densely arranged portion of the detector module, and the densely arranged portion of the device in the same detector module is irradiated with the X-ray to achieve the high resolution CT imaging at the single section of the object.